An image sensor, such as a charge-coupled device (CCD) or focal plane array (FPA), converts photons received from a scene into electrons. The electrons can be used to generate an image of the scene. The electrons do not directly identify particular attributes of the sensed photons, such as wavelength, polarization, or phase. Such attributes may be useful in a variety of different applications, including, for example, in applications where the image is analyzed to identify objects in the scene because information such as wavelength, polarization, and phase may help properly identify objects in the scene.
Color information in a conventional digital camera is determined by allowing only photons of certain wavelengths to be passed to particular sensing elements of the image sensor, typically through the use of a color filter array (CFA), such as a Bayer filter, or the like. A CFA, however, allows for the determination of only a finite number of colors from a scene, typically three colors, and does not facilitate the identification of other attributes of photons that may be useful, such as polarization or phase. Multiple different cameras with different CFAs could be used simultaneously to capture different wavelength information, but such an arrangement increases costs and complexity.